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Thanks Dave, that makes good sense. Part of my problem was over-loading the emulsion with dichromate when exposing at 488nm, as you suggested. I watched the plate as it was being exposed and saw a huge amount of scatter coming off the emulsion (it looked a little like frosted glass) when being expos...

I've had some crystallization problems with G307. It may be due to the cool temp of 16C (60F) used when drying. When immersing the gelatin layer in the 5% solution of potassium dichromate (with a little glycerol and Photo-flo), it comes out clear, but after drying a while, white crystals form, espec...

Can you take photos? If you want to degass water for an emulsion, I recommend getting an inexpensive distiller, for example, a medical one. The resulting distillate has a low gas content in the first hours after receipt or if hermetically sealed. You can keep a gelatin solution under ultrasound for...

Thanks for the detailed info. Also, to make sure the mix was thorough, I added two-three drops of photo-flo to the gloop. So far, I haven't added photo-flo, but want to try it. When mixing my DCG (I use mag stirrer also) it's obvious that it takes some effort to mix it well. In the glass bottle of e...

In the past, I've noticed "pits" in my coated emulsion. I call them pits, because they seemed to be what Richard Rallison described in his 1994 Lake Forest notes: "These "pits" have the appearance of small circles of various sizes and scatter themselves throughout the plate....

The problem is: why are the Bragg planes twisted? My experience with Bayfol is very limited, and I have no experience with proximity copies. But once, with Bayfol, I was exposing while watching the film, and saw what looked like "movement" of the film. It was a very odd effect, it looked ...

My normal display procedure was: 1 minute fix/harden 5 minutes running water 1 minute 25% alcohol 1 minute 50% alcohol 1 minute 75% alcohol 1 minute 100% cold (room temp) alcohol 1 minute100% hot (~70 deg C) alcohol. For technical, narrow band optics, I'd go 3 minutes on the fixer, 1- 2 minute in r...

3. There may be non-uniformities in the processing, eg a temperature gradient in any of the alcohols. This will cause differential thickness across the hologram. Thanks, that's interesting. If narrowband is the goal, then I guess the traditional hot final IPA wouldn't be desired. Would it be prefer...

Super bright, and nice photo!

Looks very very bright, especially after picking up after a 15 year hiatus

I've never done a proximity copy, how do you like them?